Andrew's git / gitweb.git / fsck.c
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fsck.con commit blame: improve diagnosis for "--reverse NEW" (d993ce1)
   1#include "cache.h"
   2#include "object.h"
   3#include "blob.h"
   4#include "tree.h"
   5#include "tree-walk.h"
   6#include "commit.h"
   7#include "tag.h"
   8#include "fsck.h"
   9#include "refs.h"
  10#include "utf8.h"
  11#include "sha1-array.h"
  12
  13#define FSCK_FATAL -1
  14#define FSCK_INFO -2
  15
  16#define FOREACH_MSG_ID(FUNC) \
  17        /* fatal errors */ \
  18        FUNC(NUL_IN_HEADER, FATAL) \
  19        FUNC(UNTERMINATED_HEADER, FATAL) \
  20        /* errors */ \
  21        FUNC(BAD_DATE, ERROR) \
  22        FUNC(BAD_DATE_OVERFLOW, ERROR) \
  23        FUNC(BAD_EMAIL, ERROR) \
  24        FUNC(BAD_NAME, ERROR) \
  25        FUNC(BAD_OBJECT_SHA1, ERROR) \
  26        FUNC(BAD_PARENT_SHA1, ERROR) \
  27        FUNC(BAD_TAG_OBJECT, ERROR) \
  28        FUNC(BAD_TIMEZONE, ERROR) \
  29        FUNC(BAD_TREE, ERROR) \
  30        FUNC(BAD_TREE_SHA1, ERROR) \
  31        FUNC(BAD_TYPE, ERROR) \
  32        FUNC(DUPLICATE_ENTRIES, ERROR) \
  33        FUNC(MISSING_AUTHOR, ERROR) \
  34        FUNC(MISSING_COMMITTER, ERROR) \
  35        FUNC(MISSING_EMAIL, ERROR) \
  36        FUNC(MISSING_GRAFT, ERROR) \
  37        FUNC(MISSING_NAME_BEFORE_EMAIL, ERROR) \
  38        FUNC(MISSING_OBJECT, ERROR) \
  39        FUNC(MISSING_PARENT, ERROR) \
  40        FUNC(MISSING_SPACE_BEFORE_DATE, ERROR) \
  41        FUNC(MISSING_SPACE_BEFORE_EMAIL, ERROR) \
  42        FUNC(MISSING_TAG, ERROR) \
  43        FUNC(MISSING_TAG_ENTRY, ERROR) \
  44        FUNC(MISSING_TAG_OBJECT, ERROR) \
  45        FUNC(MISSING_TREE, ERROR) \
  46        FUNC(MISSING_TYPE, ERROR) \
  47        FUNC(MISSING_TYPE_ENTRY, ERROR) \
  48        FUNC(MULTIPLE_AUTHORS, ERROR) \
  49        FUNC(TAG_OBJECT_NOT_TAG, ERROR) \
  50        FUNC(TREE_NOT_SORTED, ERROR) \
  51        FUNC(UNKNOWN_TYPE, ERROR) \
  52        FUNC(ZERO_PADDED_DATE, ERROR) \
  53        /* warnings */ \
  54        FUNC(BAD_FILEMODE, WARN) \
  55        FUNC(EMPTY_NAME, WARN) \
  56        FUNC(FULL_PATHNAME, WARN) \
  57        FUNC(HAS_DOT, WARN) \
  58        FUNC(HAS_DOTDOT, WARN) \
  59        FUNC(HAS_DOTGIT, WARN) \
  60        FUNC(NULL_SHA1, WARN) \
  61        FUNC(ZERO_PADDED_FILEMODE, WARN) \
  62        FUNC(NUL_IN_COMMIT, WARN) \
  63        /* infos (reported as warnings, but ignored by default) */ \
  64        FUNC(BAD_TAG_NAME, INFO) \
  65        FUNC(MISSING_TAGGER_ENTRY, INFO)
  66
  67#define MSG_ID(id, msg_type) FSCK_MSG_##id,
  68enum fsck_msg_id {
  69        FOREACH_MSG_ID(MSG_ID)
  70        FSCK_MSG_MAX
  71};
  72#undef MSG_ID
  73
  74#define STR(x) #x
  75#define MSG_ID(id, msg_type) { STR(id), NULL, FSCK_##msg_type },
  76static struct {
  77        const char *id_string;
  78        const char *downcased;
  79        int msg_type;
  80} msg_id_info[FSCK_MSG_MAX + 1] = {
  81        FOREACH_MSG_ID(MSG_ID)
  82        { NULL, NULL, -1 }
  83};
  84#undef MSG_ID
  85
  86static int parse_msg_id(const char *text)
  87{
  88        int i;
  89
  90        if (!msg_id_info[0].downcased) {
  91                /* convert id_string to lower case, without underscores. */
  92                for (i = 0; i < FSCK_MSG_MAX; i++) {
  93                        const char *p = msg_id_info[i].id_string;
  94                        int len = strlen(p);
  95                        char *q = xmalloc(len);
  96
  97                        msg_id_info[i].downcased = q;
  98                        while (*p)
  99                                if (*p == '_')
 100                                        p++;
 101                                else
 102                                        *(q)++ = tolower(*(p)++);
 103                        *q = '\0';
 104                }
 105        }
 106
 107        for (i = 0; i < FSCK_MSG_MAX; i++)
 108                if (!strcmp(text, msg_id_info[i].downcased))
 109                        return i;
 110
 111        return -1;
 112}
 113
 114static int fsck_msg_type(enum fsck_msg_id msg_id,
 115        struct fsck_options *options)
 116{
 117        int msg_type;
 118
 119        assert(msg_id >= 0 && msg_id < FSCK_MSG_MAX);
 120
 121        if (options->msg_type)
 122                msg_type = options->msg_type[msg_id];
 123        else {
 124                msg_type = msg_id_info[msg_id].msg_type;
 125                if (options->strict && msg_type == FSCK_WARN)
 126                        msg_type = FSCK_ERROR;
 127        }
 128
 129        return msg_type;
 130}
 131
 132static void init_skiplist(struct fsck_options *options, const char *path)
 133{
 134        static struct sha1_array skiplist = SHA1_ARRAY_INIT;
 135        int sorted, fd;
 136        char buffer[41];
 137        unsigned char sha1[20];
 138
 139        if (options->skiplist)
 140                sorted = options->skiplist->sorted;
 141        else {
 142                sorted = 1;
 143                options->skiplist = &skiplist;
 144        }
 145
 146        fd = open(path, O_RDONLY);
 147        if (fd < 0)
 148                die("Could not open skip list: %s", path);
 149        for (;;) {
 150                int result = read_in_full(fd, buffer, sizeof(buffer));
 151                if (result < 0)
 152                        die_errno("Could not read '%s'", path);
 153                if (!result)
 154                        break;
 155                if (get_sha1_hex(buffer, sha1) || buffer[40] != '\n')
 156                        die("Invalid SHA-1: %s", buffer);
 157                sha1_array_append(&skiplist, sha1);
 158                if (sorted && skiplist.nr > 1 &&
 159                                hashcmp(skiplist.sha1[skiplist.nr - 2],
 160                                        sha1) > 0)
 161                        sorted = 0;
 162        }
 163        close(fd);
 164
 165        if (sorted)
 166                skiplist.sorted = 1;
 167}
 168
 169static int parse_msg_type(const char *str)
 170{
 171        if (!strcmp(str, "error"))
 172                return FSCK_ERROR;
 173        else if (!strcmp(str, "warn"))
 174                return FSCK_WARN;
 175        else if (!strcmp(str, "ignore"))
 176                return FSCK_IGNORE;
 177        else
 178                die("Unknown fsck message type: '%s'", str);
 179}
 180
 181int is_valid_msg_type(const char *msg_id, const char *msg_type)
 182{
 183        if (parse_msg_id(msg_id) < 0)
 184                return 0;
 185        parse_msg_type(msg_type);
 186        return 1;
 187}
 188
 189void fsck_set_msg_type(struct fsck_options *options,
 190                const char *msg_id, const char *msg_type)
 191{
 192        int id = parse_msg_id(msg_id), type;
 193
 194        if (id < 0)
 195                die("Unhandled message id: %s", msg_id);
 196        type = parse_msg_type(msg_type);
 197
 198        if (type != FSCK_ERROR && msg_id_info[id].msg_type == FSCK_FATAL)
 199                die("Cannot demote %s to %s", msg_id, msg_type);
 200
 201        if (!options->msg_type) {
 202                int i;
 203                int *msg_type;
 204                ALLOC_ARRAY(msg_type, FSCK_MSG_MAX);
 205                for (i = 0; i < FSCK_MSG_MAX; i++)
 206                        msg_type[i] = fsck_msg_type(i, options);
 207                options->msg_type = msg_type;
 208        }
 209
 210        options->msg_type[id] = type;
 211}
 212
 213void fsck_set_msg_types(struct fsck_options *options, const char *values)
 214{
 215        char *buf = xstrdup(values), *to_free = buf;
 216        int done = 0;
 217
 218        while (!done) {
 219                int len = strcspn(buf, " ,|"), equal;
 220
 221                done = !buf[len];
 222                if (!len) {
 223                        buf++;
 224                        continue;
 225                }
 226                buf[len] = '\0';
 227
 228                for (equal = 0;
 229                     equal < len && buf[equal] != '=' && buf[equal] != ':';
 230                     equal++)
 231                        buf[equal] = tolower(buf[equal]);
 232                buf[equal] = '\0';
 233
 234                if (!strcmp(buf, "skiplist")) {
 235                        if (equal == len)
 236                                die("skiplist requires a path");
 237                        init_skiplist(options, buf + equal + 1);
 238                        buf += len + 1;
 239                        continue;
 240                }
 241
 242                if (equal == len)
 243                        die("Missing '=': '%s'", buf);
 244
 245                fsck_set_msg_type(options, buf, buf + equal + 1);
 246                buf += len + 1;
 247        }
 248        free(to_free);
 249}
 250
 251static void append_msg_id(struct strbuf *sb, const char *msg_id)
 252{
 253        for (;;) {
 254                char c = *(msg_id)++;
 255
 256                if (!c)
 257                        break;
 258                if (c != '_')
 259                        strbuf_addch(sb, tolower(c));
 260                else {
 261                        assert(*msg_id);
 262                        strbuf_addch(sb, *(msg_id)++);
 263                }
 264        }
 265
 266        strbuf_addstr(sb, ": ");
 267}
 268
 269__attribute__((format (printf, 4, 5)))
 270static int report(struct fsck_options *options, struct object *object,
 271        enum fsck_msg_id id, const char *fmt, ...)
 272{
 273        va_list ap;
 274        struct strbuf sb = STRBUF_INIT;
 275        int msg_type = fsck_msg_type(id, options), result;
 276
 277        if (msg_type == FSCK_IGNORE)
 278                return 0;
 279
 280        if (options->skiplist && object &&
 281                        sha1_array_lookup(options->skiplist, object->oid.hash) >= 0)
 282                return 0;
 283
 284        if (msg_type == FSCK_FATAL)
 285                msg_type = FSCK_ERROR;
 286        else if (msg_type == FSCK_INFO)
 287                msg_type = FSCK_WARN;
 288
 289        append_msg_id(&sb, msg_id_info[id].id_string);
 290
 291        va_start(ap, fmt);
 292        strbuf_vaddf(&sb, fmt, ap);
 293        result = options->error_func(object, msg_type, sb.buf);
 294        strbuf_release(&sb);
 295        va_end(ap);
 296
 297        return result;
 298}
 299
 300static int fsck_walk_tree(struct tree *tree, void *data, struct fsck_options *options)
 301{
 302        struct tree_desc desc;
 303        struct name_entry entry;
 304        int res = 0;
 305
 306        if (parse_tree(tree))
 307                return -1;
 308
 309        init_tree_desc(&desc, tree->buffer, tree->size);
 310        while (tree_entry(&desc, &entry)) {
 311                int result;
 312
 313                if (S_ISGITLINK(entry.mode))
 314                        continue;
 315                if (S_ISDIR(entry.mode))
 316                        result = options->walk(&lookup_tree(entry.sha1)->object, OBJ_TREE, data, options);
 317                else if (S_ISREG(entry.mode) || S_ISLNK(entry.mode))
 318                        result = options->walk(&lookup_blob(entry.sha1)->object, OBJ_BLOB, data, options);
 319                else {
 320                        result = error("in tree %s: entry %s has bad mode %.6o",
 321                                        oid_to_hex(&tree->object.oid), entry.path, entry.mode);
 322                }
 323                if (result < 0)
 324                        return result;
 325                if (!res)
 326                        res = result;
 327        }
 328        return res;
 329}
 330
 331static int fsck_walk_commit(struct commit *commit, void *data, struct fsck_options *options)
 332{
 333        struct commit_list *parents;
 334        int res;
 335        int result;
 336
 337        if (parse_commit(commit))
 338                return -1;
 339
 340        result = options->walk((struct object *)commit->tree, OBJ_TREE, data, options);
 341        if (result < 0)
 342                return result;
 343        res = result;
 344
 345        parents = commit->parents;
 346        while (parents) {
 347                result = options->walk((struct object *)parents->item, OBJ_COMMIT, data, options);
 348                if (result < 0)
 349                        return result;
 350                if (!res)
 351                        res = result;
 352                parents = parents->next;
 353        }
 354        return res;
 355}
 356
 357static int fsck_walk_tag(struct tag *tag, void *data, struct fsck_options *options)
 358{
 359        if (parse_tag(tag))
 360                return -1;
 361        return options->walk(tag->tagged, OBJ_ANY, data, options);
 362}
 363
 364int fsck_walk(struct object *obj, void *data, struct fsck_options *options)
 365{
 366        if (!obj)
 367                return -1;
 368        switch (obj->type) {
 369        case OBJ_BLOB:
 370                return 0;
 371        case OBJ_TREE:
 372                return fsck_walk_tree((struct tree *)obj, data, options);
 373        case OBJ_COMMIT:
 374                return fsck_walk_commit((struct commit *)obj, data, options);
 375        case OBJ_TAG:
 376                return fsck_walk_tag((struct tag *)obj, data, options);
 377        default:
 378                error("Unknown object type for %s", oid_to_hex(&obj->oid));
 379                return -1;
 380        }
 381}
 382
 383/*
 384 * The entries in a tree are ordered in the _path_ order,
 385 * which means that a directory entry is ordered by adding
 386 * a slash to the end of it.
 387 *
 388 * So a directory called "a" is ordered _after_ a file
 389 * called "a.c", because "a/" sorts after "a.c".
 390 */
 391#define TREE_UNORDERED (-1)
 392#define TREE_HAS_DUPS  (-2)
 393
 394static int verify_ordered(unsigned mode1, const char *name1, unsigned mode2, const char *name2)
 395{
 396        int len1 = strlen(name1);
 397        int len2 = strlen(name2);
 398        int len = len1 < len2 ? len1 : len2;
 399        unsigned char c1, c2;
 400        int cmp;
 401
 402        cmp = memcmp(name1, name2, len);
 403        if (cmp < 0)
 404                return 0;
 405        if (cmp > 0)
 406                return TREE_UNORDERED;
 407
 408        /*
 409         * Ok, the first <len> characters are the same.
 410         * Now we need to order the next one, but turn
 411         * a '\0' into a '/' for a directory entry.
 412         */
 413        c1 = name1[len];
 414        c2 = name2[len];
 415        if (!c1 && !c2)
 416                /*
 417                 * git-write-tree used to write out a nonsense tree that has
 418                 * entries with the same name, one blob and one tree.  Make
 419                 * sure we do not have duplicate entries.
 420                 */
 421                return TREE_HAS_DUPS;
 422        if (!c1 && S_ISDIR(mode1))
 423                c1 = '/';
 424        if (!c2 && S_ISDIR(mode2))
 425                c2 = '/';
 426        return c1 < c2 ? 0 : TREE_UNORDERED;
 427}
 428
 429static int fsck_tree(struct tree *item, struct fsck_options *options)
 430{
 431        int retval;
 432        int has_null_sha1 = 0;
 433        int has_full_path = 0;
 434        int has_empty_name = 0;
 435        int has_dot = 0;
 436        int has_dotdot = 0;
 437        int has_dotgit = 0;
 438        int has_zero_pad = 0;
 439        int has_bad_modes = 0;
 440        int has_dup_entries = 0;
 441        int not_properly_sorted = 0;
 442        struct tree_desc desc;
 443        unsigned o_mode;
 444        const char *o_name;
 445
 446        init_tree_desc(&desc, item->buffer, item->size);
 447
 448        o_mode = 0;
 449        o_name = NULL;
 450
 451        while (desc.size) {
 452                unsigned mode;
 453                const char *name;
 454                const unsigned char *sha1;
 455
 456                sha1 = tree_entry_extract(&desc, &name, &mode);
 457
 458                has_null_sha1 |= is_null_sha1(sha1);
 459                has_full_path |= !!strchr(name, '/');
 460                has_empty_name |= !*name;
 461                has_dot |= !strcmp(name, ".");
 462                has_dotdot |= !strcmp(name, "..");
 463                has_dotgit |= (!strcmp(name, ".git") ||
 464                               is_hfs_dotgit(name) ||
 465                               is_ntfs_dotgit(name));
 466                has_zero_pad |= *(char *)desc.buffer == '0';
 467                update_tree_entry(&desc);
 468
 469                switch (mode) {
 470                /*
 471                 * Standard modes..
 472                 */
 473                case S_IFREG | 0755:
 474                case S_IFREG | 0644:
 475                case S_IFLNK:
 476                case S_IFDIR:
 477                case S_IFGITLINK:
 478                        break;
 479                /*
 480                 * This is nonstandard, but we had a few of these
 481                 * early on when we honored the full set of mode
 482                 * bits..
 483                 */
 484                case S_IFREG | 0664:
 485                        if (!options->strict)
 486                                break;
 487                default:
 488                        has_bad_modes = 1;
 489                }
 490
 491                if (o_name) {
 492                        switch (verify_ordered(o_mode, o_name, mode, name)) {
 493                        case TREE_UNORDERED:
 494                                not_properly_sorted = 1;
 495                                break;
 496                        case TREE_HAS_DUPS:
 497                                has_dup_entries = 1;
 498                                break;
 499                        default:
 500                                break;
 501                        }
 502                }
 503
 504                o_mode = mode;
 505                o_name = name;
 506        }
 507
 508        retval = 0;
 509        if (has_null_sha1)
 510                retval += report(options, &item->object, FSCK_MSG_NULL_SHA1, "contains entries pointing to null sha1");
 511        if (has_full_path)
 512                retval += report(options, &item->object, FSCK_MSG_FULL_PATHNAME, "contains full pathnames");
 513        if (has_empty_name)
 514                retval += report(options, &item->object, FSCK_MSG_EMPTY_NAME, "contains empty pathname");
 515        if (has_dot)
 516                retval += report(options, &item->object, FSCK_MSG_HAS_DOT, "contains '.'");
 517        if (has_dotdot)
 518                retval += report(options, &item->object, FSCK_MSG_HAS_DOTDOT, "contains '..'");
 519        if (has_dotgit)
 520                retval += report(options, &item->object, FSCK_MSG_HAS_DOTGIT, "contains '.git'");
 521        if (has_zero_pad)
 522                retval += report(options, &item->object, FSCK_MSG_ZERO_PADDED_FILEMODE, "contains zero-padded file modes");
 523        if (has_bad_modes)
 524                retval += report(options, &item->object, FSCK_MSG_BAD_FILEMODE, "contains bad file modes");
 525        if (has_dup_entries)
 526                retval += report(options, &item->object, FSCK_MSG_DUPLICATE_ENTRIES, "contains duplicate file entries");
 527        if (not_properly_sorted)
 528                retval += report(options, &item->object, FSCK_MSG_TREE_NOT_SORTED, "not properly sorted");
 529        return retval;
 530}
 531
 532static int verify_headers(const void *data, unsigned long size,
 533                          struct object *obj, struct fsck_options *options)
 534{
 535        const char *buffer = (const char *)data;
 536        unsigned long i;
 537
 538        for (i = 0; i < size; i++) {
 539                switch (buffer[i]) {
 540                case '\0':
 541                        return report(options, obj,
 542                                FSCK_MSG_NUL_IN_HEADER,
 543                                "unterminated header: NUL at offset %ld", i);
 544                case '\n':
 545                        if (i + 1 < size && buffer[i + 1] == '\n')
 546                                return 0;
 547                }
 548        }
 549
 550        /*
 551         * We did not find double-LF that separates the header
 552         * and the body.  Not having a body is not a crime but
 553         * we do want to see the terminating LF for the last header
 554         * line.
 555         */
 556        if (size && buffer[size - 1] == '\n')
 557                return 0;
 558
 559        return report(options, obj,
 560                FSCK_MSG_UNTERMINATED_HEADER, "unterminated header");
 561}
 562
 563static int fsck_ident(const char **ident, struct object *obj, struct fsck_options *options)
 564{
 565        const char *p = *ident;
 566        char *end;
 567
 568        *ident = strchrnul(*ident, '\n');
 569        if (**ident == '\n')
 570                (*ident)++;
 571
 572        if (*p == '<')
 573                return report(options, obj, FSCK_MSG_MISSING_NAME_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
 574        p += strcspn(p, "<>\n");
 575        if (*p == '>')
 576                return report(options, obj, FSCK_MSG_BAD_NAME, "invalid author/committer line - bad name");
 577        if (*p != '<')
 578                return report(options, obj, FSCK_MSG_MISSING_EMAIL, "invalid author/committer line - missing email");
 579        if (p[-1] != ' ')
 580                return report(options, obj, FSCK_MSG_MISSING_SPACE_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
 581        p++;
 582        p += strcspn(p, "<>\n");
 583        if (*p != '>')
 584                return report(options, obj, FSCK_MSG_BAD_EMAIL, "invalid author/committer line - bad email");
 585        p++;
 586        if (*p != ' ')
 587                return report(options, obj, FSCK_MSG_MISSING_SPACE_BEFORE_DATE, "invalid author/committer line - missing space before date");
 588        p++;
 589        if (*p == '0' && p[1] != ' ')
 590                return report(options, obj, FSCK_MSG_ZERO_PADDED_DATE, "invalid author/committer line - zero-padded date");
 591        if (date_overflows(strtoul(p, &end, 10)))
 592                return report(options, obj, FSCK_MSG_BAD_DATE_OVERFLOW, "invalid author/committer line - date causes integer overflow");
 593        if ((end == p || *end != ' '))
 594                return report(options, obj, FSCK_MSG_BAD_DATE, "invalid author/committer line - bad date");
 595        p = end + 1;
 596        if ((*p != '+' && *p != '-') ||
 597            !isdigit(p[1]) ||
 598            !isdigit(p[2]) ||
 599            !isdigit(p[3]) ||
 600            !isdigit(p[4]) ||
 601            (p[5] != '\n'))
 602                return report(options, obj, FSCK_MSG_BAD_TIMEZONE, "invalid author/committer line - bad time zone");
 603        p += 6;
 604        return 0;
 605}
 606
 607static int fsck_commit_buffer(struct commit *commit, const char *buffer,
 608        unsigned long size, struct fsck_options *options)
 609{
 610        unsigned char tree_sha1[20], sha1[20];
 611        struct commit_graft *graft;
 612        unsigned parent_count, parent_line_count = 0, author_count;
 613        int err;
 614        const char *buffer_begin = buffer;
 615
 616        if (verify_headers(buffer, size, &commit->object, options))
 617                return -1;
 618
 619        if (!skip_prefix(buffer, "tree ", &buffer))
 620                return report(options, &commit->object, FSCK_MSG_MISSING_TREE, "invalid format - expected 'tree' line");
 621        if (get_sha1_hex(buffer, tree_sha1) || buffer[40] != '\n') {
 622                err = report(options, &commit->object, FSCK_MSG_BAD_TREE_SHA1, "invalid 'tree' line format - bad sha1");
 623                if (err)
 624                        return err;
 625        }
 626        buffer += 41;
 627        while (skip_prefix(buffer, "parent ", &buffer)) {
 628                if (get_sha1_hex(buffer, sha1) || buffer[40] != '\n') {
 629                        err = report(options, &commit->object, FSCK_MSG_BAD_PARENT_SHA1, "invalid 'parent' line format - bad sha1");
 630                        if (err)
 631                                return err;
 632                }
 633                buffer += 41;
 634                parent_line_count++;
 635        }
 636        graft = lookup_commit_graft(commit->object.oid.hash);
 637        parent_count = commit_list_count(commit->parents);
 638        if (graft) {
 639                if (graft->nr_parent == -1 && !parent_count)
 640                        ; /* shallow commit */
 641                else if (graft->nr_parent != parent_count) {
 642                        err = report(options, &commit->object, FSCK_MSG_MISSING_GRAFT, "graft objects missing");
 643                        if (err)
 644                                return err;
 645                }
 646        } else {
 647                if (parent_count != parent_line_count) {
 648                        err = report(options, &commit->object, FSCK_MSG_MISSING_PARENT, "parent objects missing");
 649                        if (err)
 650                                return err;
 651                }
 652        }
 653        author_count = 0;
 654        while (skip_prefix(buffer, "author ", &buffer)) {
 655                author_count++;
 656                err = fsck_ident(&buffer, &commit->object, options);
 657                if (err)
 658                        return err;
 659        }
 660        if (author_count < 1)
 661                err = report(options, &commit->object, FSCK_MSG_MISSING_AUTHOR, "invalid format - expected 'author' line");
 662        else if (author_count > 1)
 663                err = report(options, &commit->object, FSCK_MSG_MULTIPLE_AUTHORS, "invalid format - multiple 'author' lines");
 664        if (err)
 665                return err;
 666        if (!skip_prefix(buffer, "committer ", &buffer))
 667                return report(options, &commit->object, FSCK_MSG_MISSING_COMMITTER, "invalid format - expected 'committer' line");
 668        err = fsck_ident(&buffer, &commit->object, options);
 669        if (err)
 670                return err;
 671        if (!commit->tree) {
 672                err = report(options, &commit->object, FSCK_MSG_BAD_TREE, "could not load commit's tree %s", sha1_to_hex(tree_sha1));
 673                if (err)
 674                        return err;
 675        }
 676        if (memchr(buffer_begin, '\0', size)) {
 677                err = report(options, &commit->object, FSCK_MSG_NUL_IN_COMMIT,
 678                             "NUL byte in the commit object body");
 679                if (err)
 680                        return err;
 681        }
 682        return 0;
 683}
 684
 685static int fsck_commit(struct commit *commit, const char *data,
 686        unsigned long size, struct fsck_options *options)
 687{
 688        const char *buffer = data ?  data : get_commit_buffer(commit, &size);
 689        int ret = fsck_commit_buffer(commit, buffer, size, options);
 690        if (!data)
 691                unuse_commit_buffer(commit, buffer);
 692        return ret;
 693}
 694
 695static int fsck_tag_buffer(struct tag *tag, const char *data,
 696        unsigned long size, struct fsck_options *options)
 697{
 698        unsigned char sha1[20];
 699        int ret = 0;
 700        const char *buffer;
 701        char *to_free = NULL, *eol;
 702        struct strbuf sb = STRBUF_INIT;
 703
 704        if (data)
 705                buffer = data;
 706        else {
 707                enum object_type type;
 708
 709                buffer = to_free =
 710                        read_sha1_file(tag->object.oid.hash, &type, &size);
 711                if (!buffer)
 712                        return report(options, &tag->object,
 713                                FSCK_MSG_MISSING_TAG_OBJECT,
 714                                "cannot read tag object");
 715
 716                if (type != OBJ_TAG) {
 717                        ret = report(options, &tag->object,
 718                                FSCK_MSG_TAG_OBJECT_NOT_TAG,
 719                                "expected tag got %s",
 720                            typename(type));
 721                        goto done;
 722                }
 723        }
 724
 725        ret = verify_headers(buffer, size, &tag->object, options);
 726        if (ret)
 727                goto done;
 728
 729        if (!skip_prefix(buffer, "object ", &buffer)) {
 730                ret = report(options, &tag->object, FSCK_MSG_MISSING_OBJECT, "invalid format - expected 'object' line");
 731                goto done;
 732        }
 733        if (get_sha1_hex(buffer, sha1) || buffer[40] != '\n') {
 734                ret = report(options, &tag->object, FSCK_MSG_BAD_OBJECT_SHA1, "invalid 'object' line format - bad sha1");
 735                if (ret)
 736                        goto done;
 737        }
 738        buffer += 41;
 739
 740        if (!skip_prefix(buffer, "type ", &buffer)) {
 741                ret = report(options, &tag->object, FSCK_MSG_MISSING_TYPE_ENTRY, "invalid format - expected 'type' line");
 742                goto done;
 743        }
 744        eol = strchr(buffer, '\n');
 745        if (!eol) {
 746                ret = report(options, &tag->object, FSCK_MSG_MISSING_TYPE, "invalid format - unexpected end after 'type' line");
 747                goto done;
 748        }
 749        if (type_from_string_gently(buffer, eol - buffer, 1) < 0)
 750                ret = report(options, &tag->object, FSCK_MSG_BAD_TYPE, "invalid 'type' value");
 751        if (ret)
 752                goto done;
 753        buffer = eol + 1;
 754
 755        if (!skip_prefix(buffer, "tag ", &buffer)) {
 756                ret = report(options, &tag->object, FSCK_MSG_MISSING_TAG_ENTRY, "invalid format - expected 'tag' line");
 757                goto done;
 758        }
 759        eol = strchr(buffer, '\n');
 760        if (!eol) {
 761                ret = report(options, &tag->object, FSCK_MSG_MISSING_TAG, "invalid format - unexpected end after 'type' line");
 762                goto done;
 763        }
 764        strbuf_addf(&sb, "refs/tags/%.*s", (int)(eol - buffer), buffer);
 765        if (check_refname_format(sb.buf, 0)) {
 766                ret = report(options, &tag->object, FSCK_MSG_BAD_TAG_NAME,
 767                           "invalid 'tag' name: %.*s",
 768                           (int)(eol - buffer), buffer);
 769                if (ret)
 770                        goto done;
 771        }
 772        buffer = eol + 1;
 773
 774        if (!skip_prefix(buffer, "tagger ", &buffer)) {
 775                /* early tags do not contain 'tagger' lines; warn only */
 776                ret = report(options, &tag->object, FSCK_MSG_MISSING_TAGGER_ENTRY, "invalid format - expected 'tagger' line");
 777                if (ret)
 778                        goto done;
 779        }
 780        else
 781                ret = fsck_ident(&buffer, &tag->object, options);
 782
 783done:
 784        strbuf_release(&sb);
 785        free(to_free);
 786        return ret;
 787}
 788
 789static int fsck_tag(struct tag *tag, const char *data,
 790        unsigned long size, struct fsck_options *options)
 791{
 792        struct object *tagged = tag->tagged;
 793
 794        if (!tagged)
 795                return report(options, &tag->object, FSCK_MSG_BAD_TAG_OBJECT, "could not load tagged object");
 796
 797        return fsck_tag_buffer(tag, data, size, options);
 798}
 799
 800int fsck_object(struct object *obj, void *data, unsigned long size,
 801        struct fsck_options *options)
 802{
 803        if (!obj)
 804                return report(options, obj, FSCK_MSG_BAD_OBJECT_SHA1, "no valid object to fsck");
 805
 806        if (obj->type == OBJ_BLOB)
 807                return 0;
 808        if (obj->type == OBJ_TREE)
 809                return fsck_tree((struct tree *) obj, options);
 810        if (obj->type == OBJ_COMMIT)
 811                return fsck_commit((struct commit *) obj, (const char *) data,
 812                        size, options);
 813        if (obj->type == OBJ_TAG)
 814                return fsck_tag((struct tag *) obj, (const char *) data,
 815                        size, options);
 816
 817        return report(options, obj, FSCK_MSG_UNKNOWN_TYPE, "unknown type '%d' (internal fsck error)",
 818                          obj->type);
 819}
 820
 821int fsck_error_function(struct object *obj, int msg_type, const char *message)
 822{
 823        if (msg_type == FSCK_WARN) {
 824                warning("object %s: %s", oid_to_hex(&obj->oid), message);
 825                return 0;
 826        }
 827        error("object %s: %s", oid_to_hex(&obj->oid), message);
 828        return 1;
 829}